During the baseline visit you will receive a small, hand-held personal phone and be trained in how to use it. You will carry this phone with you for 4 weeks. You will use the phone to answer questions about your mood, stress, and smoking-related issues. You will be asked to fill out some questions on the phone each time you have an urge to smoke. Also, the phone will "beep" at random and set times and ask that you answer some questions. This phone will not wake you during the night and you will be able to wait to answer questions for a few minutes if it goes off when you are busy. Answering the questions should take about 5-10 minutes. This small, hand-held personal phone will also have a GPS system activated that will record where you are during the waking hours every day while you are on study.